Sleep guidance system and related methods

ABSTRACT

A sleep efficiency monitor and methods for pacing and leading a sleeper through an optimal sleep pattern. Embodiments of the present invention include a physiological characteristic monitor for monitoring the sleep stages of a sleeper, a sensory stimulus generator for generating stimulus to affect the sleep stages of a sleeper, and a processor for determining what sleep stage the sleeper is in and what sensory stimulus is needed to cause the sleeper to move to another sleep stage. A personalized sleep profile may also be established for the sleeper and sleep guided in accordance with the profile parameters to optimize a sleep session. By providing sensory stimulus to a sleeper, the sleeper may be guided through the various sleep stages in an optimal pattern so that the sleeper awakens refreshed even if sleep is disrupted during the night or the sleeper&#39;s allotted sleep period is different than usual. Embodiments of the invention also involve calibration of the sleep guidance system to a particular sleeper.

This application is a divisional of Ser. No. 10/718,960, filed on Nov.21, 2003 now U.S. Pat. No. 7,041,049.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention generally relates to sleep efficiency devices, and morespecifically to a device and method for monitoring a person's sleeppatterns through the person's physiological characteristics, determiningan efficient sleep pattern, establishing a rapport between the personand a sleep guide, and guiding the person through one or more sleeppatterns.

2. Background Art

Research indicates that a healthy adult sleeps an average of 7.5 hourseach night and that most people sleep between 6.5 and 8.5 hours pernight. Scientists do not know every facet of the sleeping process.However, researchers have determined that the sleeping process is apredictable cycle whose intervals are observable and may be monitoredand examined clinically with polysomnography. Polysomnography providesdata regarding electrical and muscular states during sleep.

Tracking the brain waves of sleepers using electroencephalographs(EEGs), researchers have currently identified and labeled six stages ofsleep (including a pre-sleep stage), each stage characterized bydistinctive brain-wave frequencies and patterns, as well as otherphysiological characteristics. Stage 0 is the pre-sleep stage and ischaracterized by low amplitude, high frequency alpha waves in the brain.At this stage, a person becomes relaxed, drowsy, and closes their eyes.Stages 1 through 4 are sometimes called non-rapid eye movement sleep(ANREM@ sleep). Stage 1 is characterized by the sleeper's eyes rolling,and rhythmic alpha waves which give way to irregular theta waves thatare lower in amplitude and have a lower frequency as the person losesresponsiveness to stimuli. Stage 1 may last for five or ten minutes.Stage 2 is characterized by slower, larger brain waves punctuated byhigh frequency bursts of brain activity called sleep spindles which aremarked by muscle tension. Stage 2 sleep is accompanied by a gradualdecline in heart rate, respiration and temperature as the body preparesto enter deep sleep. Stages 3 and 4 normally occur 30 to 45 minutesafter falling asleep. In Stage 3, there are fewer sleep spindles, buthigh amplitude and low frequency delta waves appear. Stage 4 ischaracterized by the high amplitude and low frequency delta wavesappearing more than 50 percent of the time. The delta waves identify thedeepest levels of sleep, when the heart rate, body temperature,respiration and blood flow to the brain are dramatically reduced, andgrowth hormones are secreted in the body. A person roused from Stage 4sleep will be groggy and confused. Altogether, it takes between 30 and120 minutes to complete NREM sleep. The pattern of the normal sleepcycle is: Stage 1, 2, 3, 4, 3, 2, Rapid Eye Movement Sleep. This cyclemay repeat (often omitting Stage 1 during subsequent cycles), until asleeper is awakened or sleep is disrupted. If the sleeper returns backto sleep, the stages may begin again, failing to complete the cycle.

Rapid eye movement sleep (AREM@ sleep) makes up about 20 percent ofsleep time. After REM sleep has begun, it is interspersed with NREMsleep every 30 to 40 minutes through the night. It is during REM sleepthat dreams are experienced. In the REM sleep stage, the same fastfrequency, low-amplitude beta waves that characterize waking statesoccur, and a person's physiological signs—heart rate, breathing, andblood pressure—also resemble those in the waking state. However, muscletone decreases to the point of paralysis, with sudden twitches,especially in the face, hands and legs. REM sleep periods may last from10 minutes at the beginning of a sleep cycle to one hour at the end ofit.

Research has found that most people complete four to six complete sleepcycles each night, with each cycle lasting about 90 to 100 minutes.These cycles vary in composition, however; early in the night most ofthe time is spent in Stage 3 and 4 sleep, with Stage 2 and REM sleeppredominating later on. Sleep patterns also may vary in the course of aperson's life. On the average, an infant sleeps about 16 hours a day, incontrast to a 70-year-old who sleeps only about six hours a day. WhileREM sleep comprises about half of total sleep at birth, it eventuallydecreases to only about 25 percent of total sleep in old age. Sleepingpatterns also vary greatly among individuals, and even among differentcultures (in terms of napping, for example).

Regardless of the optimal sleep cycle or pattern for any particularperson, many people have difficulty sleeping, are awakened in the middleof a sleep cycle, or otherwise do not have optimal sleep or do not usetheir sleep time as well as they could. To overcome sleep-relatedproblems, many sleepers take sleep inducing or assisting drugs, attendpsychological therapy, try relaxing techniques prior to sleeping, orjust deal with not sleeping well. Many other sleepers do not realizethey are not sleeping well and are, nonetheless, suffering theconsequences of inefficient sleep. It would be advantageous to manysleepers to have a method for obtaining efficient sleep periodsregardless of the person, their environment, and the time available forsleep.

DISCLOSURE OF THE INVENTION

The present invention relates to sleeping and methods and apparatus forobtaining efficient sleep and using sleep time more productively.Through the principles of pacing and leading, a rapport may beestablished with a sleeper's unconscious to cause the sleeper totransition through the various stages of sleep. As used herein, the termAstage@ as it refers to stages of sleep is intended to refer not only tothe six stages of sleep referred to in the current popular sleepliterature, but also is intended to refer to and include all forms ofrecognizable sleep states, stages and patterns as well as physiologicalcharacteristic patterns that a particular sleeper may experience on aregular basis. When a person sleeps, whether categorization of thatsleep is simplified into six stages common to all sleepers or is leftmore complex stages personal to the sleeper, the person's physiologicalcharacteristics illustrate recognizable patterns for that person. Thesepatterns identify what portion of the person's sleep patterns the personis in. It is to distinguish the sleep portions by these recognizable andmeasurable patterns for the sleeper that Astage@ is being used herein.

Embodiments of the invention include a processor coupled to variousperipherals such as one or more physiological characteristic monitors,one or more sensory stimuli generators, memory, printers, displays andother inputs and outputs. By monitoring select physiologicalcharacteristics of the sleeper, it can be determined which sleep stagethe sleeper is in, when the sleeper transitions to a different sleepstage, and whether a sleeper is following the lead of the sleep guidancesystem. One or more sensory stimuli are generated to lead the sleeperthrough the various sleep stages in an efficient manner. Processors ofembodiments of the invention may be configured to receive a desiredsleep period duration, calculate an efficient sleep cycle for thesleeper, and guide the sleeper through the efficient sleep cycle bymonitoring the physiological characteristics of the sleeper andgenerating appropriate sensory stimuli to lead the sleeper to one ormore desired sleep stages at the desired rate determined by theprocessor to meet the needs of the sleeper and or other criteria.

The foregoing and other features and advantages of the present inventionwill be apparent from the following more detailed description of theparticular embodiments of the invention, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram of a simple method of guiding a sleep patternof a sleeper;

FIG. 2 is a block diagram of a sleep guidance system configuredaccording to an embodiment of the present invention;

FIG. 3 is a top view of a sleep guidance system configured according toan embodiment of the present invention; and

FIG. 4 is a flow diagram of a more complex method of guiding a sleeppattern of a sleeper.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention relate to sleeping and achievingefficient sleep periods even when there is only little sleep timeavailable, when the sleep period is interrupted, and when the sleeperhas a particular time at which the sleeper wishes to wake up. By usingthe methods and apparatus configured according to embodiments of thepresent invention, a sleeper may be able to enjoy more efficient sleep,wake feeling more refreshed, and require less sleep than without thepresent invention.

Each person has particular sleeping habits and particular physiologicalcharacteristic patters indicative of the person's sleep. Some people mayget by on three to four hours of sleep, while others may need nine orten hours to feel refreshed. The right amount of sleep is whateverleaves the person feeling rested and alert. When sleep is interrupted,feelings of fatigue and irritability may be present the following day.Many people have difficulty falling asleep, are easily wakened fromsleep, and otherwise have inefficient sleep resulting in feelings offatigue or exhaustion, an inability to concentrate, and difficultystaying awake during the day. Because a sleeper cannot consciouslycontrol which stage of sleep the sleeper is in at any given time or howlong the sleeper will remain in a particular sleep stage, many sleepersare experiencing frustration and fatigue relating to inefficient sleeppatterns.

In public speaking, therapy and hypnosis, the principles of pacing andleading are commonly used as a way of establishing a rapport with anaudience or subject to assist the person in changing to a differentattitude or emotional state. By example, pacing in public speaking, inits most simple form, is matching or mimicking what the audience isdoing at the time. This may involve matching some characteristic of theaudience like the audience's attitude, mood, noise level, or level ofexcitement. Leading in public speaking is what the speaker says or doesthat is intended to get the audience to change its state of mind,attitude or level of excitement. If the audience follows the lead, thespeaker may have an affect to change the audience in a way desired bythe speaker. By first pacing the audience, the speaker can more easily,and often without the audience consciously being aware of it, change acharacteristic of the audience. In this way, pacing and leading worktogether as tools for enhancing effective public speaking.

Through a pacing and leading model in communications, speakers have beenfound to more readily establish a rapport with their audience. Forexample, if a client sits with crossed legs and is leaning back and aprofessional does something similar, then the two are able to establisha level of understanding. If a client talks in visual terms and makesgestures in the air, or speaks rapidly, then a professional will be ableto explain things much better and get along better with the client ifthe professional does the same. The rapport established through pacingand leading is generally understood to be more sub-conscious thanconscious.

Pacing and leading is a form of behavioral conditioning which works onanimals as well as humans. In a well known example of behavioralconditioning, Russian scientist Ivan Pavlov (1849–1936) discovered thatby producing a common stimulus each time his test subject dogs were fed,he was later able to cause the dogs to salivate even when the dogs werenot being fed by merely producing the same stimulus, i.e. a bell or awhite lab coat. In other words, by pacing the dogs with a stimulus eachtime the dogs salivated, Pavlov was then able to lead the dogs tosalivate with the same stimulus. This example illustrates the effectthat prolonged pacing and leading can have on a subject.

Leading is not a cognitive process; the subject is not consciously beinglead. When sensory stimuli is linked to the physiologicalcharacteristics of the person and the sensory input changes, thephysiological response changes. For sleep patterns, once the particularphysiological characteristics and patterns of the subject are known andto which stimuli the subject responds are known, the proper stimuli canbe provided to the sleeper at appropriate times during sleep to affectthe sleeper's sleep patterns.

Embodiments of the present invention apply the methods of pacing,leading and behavioral conditioning to sleep patterns and cycles. FIG. 1illustrates a first method of guiding a sleep pattern of a sleeper. Asan initial step in guiding the sleep pattern of a sleeper, one or morephysiological characteristics of the sleeper are monitored (Step 2).There are many physiological characteristics measured in the art thatmay identify in which sleep stage a sleeper resides at any given time.By measuring and monitoring one or more of those physiologicalcharacteristics, researchers are currently able to determine what sleepstage a sleeper is in, and when that sleeper has changed or will changeto a different sleep stage. Accordingly, an appropriately configuredprocessor may also be programmed to recognize the sleep stages andchanges between them using well-known pattern recognition techniques.Examples of physiological characteristics which are currently known tobe indications of sleep stages include, but are not limited to, thesleeper's: heart rate, pulse rate, blood pressure, brain wave patterns,muscle tension, eye movement, noises, loudness of noises, body position,body movement, rate of body movement, respiration, respiratory effort,respiratory airflow, body temperature, blood flow, blood oxygen leveland blood chemistry. Appropriate sensors and equipment for monitoringeach of these physiological characteristics are well known in the artand are available from a variety of manufacturers such as PhilipsMedical Systems of The Netherlands, Hewlett-Packard of Palo Alto,Calif., and Elixa of Albuquerque, N. Mex.

In simple embodiments of the invention, once it is determined that aperson is within a particular sleep stage, a sensory stimulus may begenerated or one or more characteristics of existing sensory stimuli maybe altered (Step 4) to lead the person toward another sleep stage.Sensory stimuli may be any stimuli that can be sensed by a sleeper. Forexample, and without limitation, sensory stimuli may include light,sound, smell, vibration, heat or cold, moisture, electric shock,adjustments to the sleeper's bed hardness or angle, or even changes inair flow such as a breeze or air content such as oxygen levels, andanything else that can be sensed by a sleeper. Adjustments which may bemade to sensory stimuli to lead the sleeper toward another sleep stagemay include, but are not limited to, adjustments in the magnitude orquantity, tone, quality, pattern, frequency, angle, composition, sourcelocation, application location or any other adjustment to sensorystimuli, however small, which can be sensed by a sleeper.

The following is a specific application of the invention for exemplarypurposes only. A sleeper's brain wave pattern, or other physiologicalcharacteristic, may be monitored to determine the sleep stage in whichthe sleeper resides. With appropriate conditioning, as described morefully below, when the brain waves reflect that the sleeper is in aparticular stage of sleep, for example Stage 1 sleep, an appropriateauditory tone of a predetermined frequency, volume and/or pattern may begenerated by an appropriate source. The auditory tone is used to pacethe sleeper by establishing a rapport with the sleeper's subconscious.Changes in the tone, such as by changing the frequency with which itchimes, is then used to lead the sleeper to the sleeper's nextconsecutive sleep stage, in this example Stage 2 sleep, or to lead thesleeper to take on certain physiological characteristics.

This process may continue, using the same or different auditory tones orother stimuli, to lead a sleeper through various sleep stages throughoutthe sleep period in an optimal manner, each time establishing a rapportand leading the sleeper through sleep. By continuously monitoring thecurrent sleep stage and physiological characteristics of the sleeperwhile it is leading the sleeper through the sleep stages, a sleepguidance system configured according to embodiments of the presentinvention can adapt a sleeper's sleep pattern for efficient sleep evenwhen sleep is disrupted. The transition from NREM sleep to REM sleep andback again is important to the sleeper feeling refreshed and thesleeper's body being rejuvenated. Accordingly, particular embodiments ofthe invention may alternatively be configured to focus primarily uponbroadly monitoring the physiological characteristics of NREM and REMsleep and generating sensory stimuli to pace and lead a sleeper to enterREM sleep from NREM sleep, or any other categorization of sleep stages,and to return to NREM sleep from REM sleep at appropriate times.

FIG. 2 illustrates an exemplary system 10 to implement the methods forembodiments of the present invention. The system 10 illustrated in FIG.2 includes a processor 12 configured, through hardware, software orboth, to communicate with each of a number of associated peripherals. Itwill be understood by those of ordinary skill in the art that theprocessor 12 may comprise a single processor 12, or may be divided intotwo or more processors 12 and that the processor 12, through theperipherals coupled to the processor 12, controls the operations of thesleep guidance system and leads the sleeper through sleep. The processor12 may be configured differently for each embodiment of the invention tocoordinate and enable the various establishing of a sleeper profile,monitoring of physiological characteristics, interpreting of thephysiological characteristic data received, mapping the sleep patternsand physiological characteristics of the sleeper throughout the sleepcycle, determining of a sleeper's current sleep stage, identifying ofwhich physiological characteristics indicate when a sleeper is about totransition to a new sleep stage and which sensory stimulicharacteristics will pace and lead the sleeper to transition to a newsleep stage, and generating of sensory stimuli to pace and lead thesleeper to the new sleep stage.

Any number of conventional and unconventional peripherals may beoperatively coupled to the processor 12 to assist in carrying-out thevarious embodiments of the invention. For example, one or morephysiological characteristic monitors (PCMs) 14 may be coupled to theprocessor for monitoring a sleeper. PCMs may include any deviceconfigured to detect any physiological characteristic. Some specificexamples of these include, but are not limited to, electrooculograms,electromyograms, electroencephalographs and other polysomnographymonitors, microphones, motion sensors, moisture sensors, muscle tensionmonitors, blood pressure cuffs, respirators, pulse oximeters,thermometers, and the like, and any other sensor that can detect aphysiological characteristic of the sleeper.

A sensory stimulus generator 16 is also operatively coupled to theprocessor 12 to communicate with the processor 12 in providing sensorystimuli to the sleeper. The sensory stimulus generator 16 may includeany device configured to generate any stimulus which may be perceived bythe sleeper through the sleeper's senses. Some specific examples ofdevices configured to generate stimuli include, but are not limited to,speakers, vibrators, lights, electric contacts, fans, heaters, coolers,and the like. The precise configuration of the sensory stimulusgenerator 16 may take many forms, but may include such forms as: earphones, a mask, a headband, a belt, a wristband, a ring, a wall mountingand any other generator, including those configured to generate stimulifrom a remote location such as an end table, a cabinet or an extensionarm near the sleeper.

Other inputs 18 and outputs 20 may also be included to assist ininteracting with the processor 12 or for receiving data from theprocessor 12. It is anticipated that in certain embodiments of theinvention, a personal computer running Microsoft Windows operatingsoftware may be used as the processor and be coupled to variousperipherals to function as the sleep guidance system. In otherembodiments, other operating systems, programming languages, or evenmerely machine code may be used. Memory 22 is also included, such as RAMand/or ROM, to enable storage of data. Additional memory 22 may also beincluded such as backup memory, memory storage devices such as compactor digital video disc memory, magnetic media memory or any other memoryconventionally used with computers for storing data. A printer 24 anddisplay 26 may also be provided.

As will be clear to those of ordinary skill in the art, embodiments of asleep guidance system according to the invention may be configured toinclude expensive equipment and processes which may only practically beavailable through a sleep clinic, or any other medical facility, or maybe more simply configured with less expensive equipment for personalhome use. For example, while electroencephalographs can often identifythe precise sleep period of a sleeper more accurately than a pulseoximeter, the cost of an electroencephalograph can be much greater thanthat of a pulse oximeter. Accordingly, it will be clear to those ofordinary skill in the art reviewing this disclosure that certainprocesses explained herein may be performed with much greater accuracyand obtaining faster results using more accurate or specializedpolysomnography equipment. It is not crucial to the invention whichparticular model or brand of peripheral or processor is used inembodiments of the invention. One of ordinary skill in the art willreadily be able to select and utilize appropriate components for a sleepguidance system from the disclosure herein.

FIG. 3 illustrates a simpler embodiment of a sleep guidance system ofthe present invention. The system 30 of FIG. 3 includes a display 32,input keypad 34, speaker 36, scroll bar 38 and an input and/or outputplug 40. Though not specifically illustrated, a processor (such as thatshown in FIG. 2) and other related hardware and software is includedwithin the housing 42 of the system 30. The display 32 may be anydisplay commonly used for electronics such as liquid crystal, lightemitting diode, laser diode, plasma, any touch sensitive display, andthe like. The input keypad 34 and scroll bar 38 may be any keypad ortouchpad technology known in the art which allows a user to inputcommands to a processor. Similarly, the particular speaker 36 used isnot crucial to the invention. The input and/or output plug 40 may be anyconnection between the processor and a peripheral device. In particularembodiments of the invention, for example, a serial or parallel datacable such as that conventionally used between a personal computer and aperipheral may be used. The input and/or output plug 40 of the presentembodiment is configured to couple to a PCM monitoring a sleeper.Alternatively, wireless PCMs and stimulus generators may be used toreduce the likelihood that the sleeper will become tangled in a wire andhave sleep disrupted by a PCM or stimulus generator attached to thesleeper. The use of wireless PCMs and sensory stimulus generators haveparticular advantage in embodiments of the present invention becausethey reduce the risk of disrupting the sleeper. Wireless communicationtechnologies are well known in the art. Some examples of wirelesscommunication technologies which may have particular application withthe present invention include, but are not limited to, Bluetoothtechnologies, WiFi, cellular technologies, radio wave technologies, redand infrared technologies, and technologies using other frequencies ofcommunication signals whether encoded or unencoded, or mixed with othercarrier signals or not.

In a more complex embodiment of the present invention, a processor withperipherals, such as that shown in FIG. 2 or 3, is configured to performone or more portions of the method shown and described with reference toFIG. 4. Hardware and software developers of physiological characteristicmonitors will understand how to appropriately configure the sleepguidance system of embodiments of the invention to accomplish themethods described below using hardware solutions, software solutions, ormore likely a combination of both.

According to the embodiment of the method of guiding the sleep stages ofa sleeper shown in FIG. 4, one or more physiological characteristics ofa sleeper are monitored by an appropriately configured processor througha PCM (Step 50). As explained previously, by monitoring thephysiological characteristics of a sleeper, it may be determined notonly in which sleep state a sleeper resides, but what physiologicalcharacteristics of the particular sleeper best indicate that the sleeperis about to transition to a particular sleep stage and which sensorystimuli is effective to lead the sleeper to a particular sleep stage. Inthis way, a personalized sleeper profile may be established for thesleeper and stored in association with the processor. The profile mayinclude any of the following, without limitation, information indicativeof the sleeper's sleep stages, physiological characteristics to indicateparticular sleep stages and transitions between sleep stages, andstimuli settings to pace and lead the sleeper through sleep.

For example, one person may evidence one particular brain wave patternor a particular frequency of brain wave peaks while transitioning to REMsleep, and another person may evidence a different brain wave pattern ora different frequency of brain wave peaks. As another example, a firstperson may have a significant change in heart rate and little noticeablechange in respiration throughout Stage 2, while a second person may havea smaller change in heart rate and a greater noticeable change inrespiration. Additionally, one sleeper may respond more readily to noiseor even verbal instructions during sleep to pace and lead the sleeper,and another sleeper may respond more readily to changes in ambienttemperature or airflow. Thus, in certain embodiments of the invention, asleep guidance system may be configured to monitor the physiologicalcharacteristics of a sleeper, to calibrate to the particular sleeppatterns and physiological characteristics of a sleeper (Step 52), andto establish a personalized sleeper profile.

Calibration to a sleeper (Step 52) may involve merely monitoring thesleep patterns and/or physiological characteristics of a sleeper, or mayadditionally involve providing sensory stimuli to the sleeper todetermine the sleeper's physiological and sleep pattern responses tothose sensory stimuli during sleep. Calibration of a sleep guidancesystem to a sleeper may involve such steps as evaluating whichphysiological characteristics most clearly indicate a change between thesleeper's sleep stages, which patterns of physiological characteristicsoccur at which portions of the sleeper's sleep cycle or under whichcircumstances, how a sleeper's physiological characteristics or sleeppatterns change when exposed to sensory stimuli, how a sleeper'sphysiological characteristics respond when sleep is disrupted, optimaldurations and patterns for a sleeper's sleep cycle, what sensory stimuliworks most effectively to pace and/or lead the sleeper through the sleepstages, and recording these or data indicative of these in the sleeper'spersonalized sleep profile. Calibration involves any process thatgathers information about the sleeper or sleeper's sleep patterns foruse in personalizing the sleep guidance process to the particularsleeper. Many other processes may be used to calibrate the method to aparticular sleeper.

By using a multi-dimensional space profile for the sleeper, known tothose of ordinary skill in the mathematical arts, multiple variables maybe tested and varied simultaneously to obtain an optimal combination ofstimuli resulting in a variety of physiological characteristicresponses. Depending upon the sleep characteristics most needed by theparticular sleeper, the multi-dimensional space profile approach willallow the sleep guidance system to focus on particular sleep benefitsneeded by the sleeper and provide the pacing and leading techniques mosteffective with the sleeper. For example, a particular default or otherestablished profile may be scaled for a particular sleeper, or byholding particular variables, such as sleep stage durations and thelike, constant while others vary. The possible variations are many, andthose of ordinary skill in the art will understand how to establish andmaintain an appropriate personal profile for affecting the pacing andleading during a sleep session from the disclosure provided herein. Itwill also be understood by those of ordinary skill in the art from thisdisclosure that the various methods of the invention do not requirecalibration to the sleeper prior to attempting to pace or lead thesleeper. The personalized profile, including any number of variables,may be formed while the sleep guidance system is pacing and leading thesleeper, or may not even be used in certain embodiments depending uponthe particular application of the invention and history of guidance withthe particular sleeper. However, prior calibration and reference to thestored personalized sleep profile may provide better results thanwithout calibration as explained more fully below.

When it is time for guiding a sleeper's sleep, one or more physiologicalcharacteristics of the sleeper are monitored (Step 54). If the sleepguidance system has been previously calibrated for the sleeper, theguidance system may be able to more easily monitor only one or twophysiological characteristics for previously evaluated indicators ofparticular sleep stages. Nevertheless, at least one physiologicalcharacteristic of the sleeper may be monitored to determine in whichsleep stage the sleeper resides (Step 56) based upon the data gatheredwhile monitoring the physiological characteristic. Polysomnographers inthe art are well versed in identifying and distinguishing between sleepstages for a sleeper based upon physiological characteristic data.

The particular sleep stage for the sleeper may optionally be determined(Step 56). The sleeper may be paced (Step 58) to begin establishing arapport with the sleeper. As will be clear to those of ordinary skill inthe art, it is not necessary to know the particular sleep stage of thesleeper, and there are instances where a predefined sleep stage may notexist. For example, sleep apnea is a common problem for some sleeperswhich does not allow the sleepers to obtain a good night sleep becausethe sleeper stops breathing for extended periods of time throughout thenight. Sleep apnea sufferers often cannot enter deep sleep and haveirregular sleeping stages because they wake up regularly throughout thenight. Nevertheless, without knowing which actual sleep stage thesleeper is in, embodiments of the present sleep guidance system may beable to pace the sleeper's breathing or other physiologicalcharacteristic and lead the sleeper to enter a deeper sleep stagewhatever the stage is. This can be accomplished, for example and withoutlimitation, by detecting a physiological characteristic pattern thatoccurs before the apnea stage starts, and then leading the sleeper to adifferent physiological pattern out of the apnea pattern so that thesleeper does not experience the sleep apnea and, thus, is able to sleepbetter. As can be seen through this example, the stages referred to inthis description are not limited to specific sleep stages, but morebroadly include physiological characteristic patterns that can bemonitored. By pacing and leading the sleeper, those physiologicalcharacteristic patterns may be altered to better utilize the sleeper'ssleep time.

Three other examples of categories of nontraditional sleep stages relateto bedwetting, sleepwalking and nightmares. By monitoring one or morephysiological characteristics of the sleeper (Steps 50 and 54),particular embodiments of the invention may be able to calibrate to thesleeper (Step 52) and determine the sleep stages (Step 56)characteristic of the sleeper about to wet the bed, begin sleepwalkingor have a nightmare. Similar to the explanation of how the system wouldpace and lead a sleeper suffering from sleep apnea, it is not necessaryto know a particular predefined sleep stage for the sleeper. The systemneed only be able to detect, recognize and respond to particularphysiological characteristic patterns indicative of the sleeper enteringa stage of sleep where undesired events are experienced. The sleeper maythen be paced (Step 58) and lead (Step 64) to a different physiologicalpattern, out of the undesirable pattern, so that the sleeper does notexperience the undesired events. As will be clear from the presentdisclosure, embodiments of the present invention may be used to helpsleepers overcome a wide variety of problems that disrupt sleep. Severalnonlimiting examples have been provided herein, but those of ordinaryskill in the art will readily be able to adapt the methods and apparatusdisclosed herein to help sleepers overcome, or perhaps avoid, many sleepproblems.

In a particular embodiment of the invention, the stimuli used to leadthe sleeper is a human or synthesized human voice providing subliminalcues or suggestions to the sleeper. When a person is asleep, the personis more apt to follow suggestions than when awake. Some people are alsomore apt to follow suggestions than other people. During calibration ofthe system and establishment of a personalized profile for the sleeper,it is contemplated that particular embodiments of the invention will useverbal suggestions as stimuli to determine whether the sleeper may bepaced and lead with verbal suggestions as well.

In another particular embodiment of the invention, verbal instructionsare provided to the sleeper during particular sleep stages or when thesleeper is exhibiting particular physiological characteristics orpatterns. During certain times of sleep, the sleeper can actually learnbetter or respond better to instruction than in other times of sleep. Inthe past, others have attempted to take advantage of this characteristicof sleepers by playing foreign language or other learning tapes whilethey sleep. Because the learning occurs best during only certain stagesof sleep, however, much of the instruction provided during the otherstages of sleep is lost. Embodiments of the present invention overcomethis challenge by monitoring the physiological characteristics of thesleeper to determine when the sleeper is most likely to learn duringsleep and providing the verbal instructions, or at least the mostimportant verbal instructions, during that stage of the sleep. Becausethe guidance systems of the present invention can also pace and lead asleeper to different stages of sleep, the system can actually lead thesleeper to an learning stage of sleep, provide verbal instructions forthe sleeper, lead and maintain the sleeper within the learning stage forlonger to ensure instruction is completed. The sleeper's learning stageof sleep may be determined during calibration and the appropriate datastored in the sleeper's personalized profile. As with any otherembodiment of the present invention, the personalized profile may beupdated and amended during subsequent use of the guidance system withthe sleeper by noting the sleeper's responses and physiologicalcharacteristics. Those of ordinary skill in the art are familiar withthe physiological characteristics exhibited during learning stages ofsleep and will readily be able to employ and adapt the systems andembodiments disclosed herein for use in helping people learn in theirsleep more efficiently.

Pacing may involve repeating a particular sensory stimulus each time aparticular physiological characteristic is monitored. To determinewhether the sensory stimuli is appropriately pacing the sleeper (Step62), one or more physiological characteristics are monitored (Step 60).Throughout the examples and discussions provided herein, where referralis made to the monitoring of a physiological characteristic, it shouldbe understood that those explanations may be applied equally tomonitoring two or more physiological characteristics. While monitoringonly one characteristic may be sufficient to practice the inventionsdescribed herein depending upon the sleeper, monitoring of multiplecharacteristics and the parametric monitoring of the multipleinteractions and variances of those characteristics and their respectivepatterns, is expected to provide more detailed indications oftransitions between sleep stages and of the effectiveness of the pacingand leading.

In one particular example of pacing, when a particular physiologicalcharacteristic threshold is detected, such as the sleeper drawing abreath, a sensory stimulus such as a short, quiet hum may be producedfrom a speaker such as the speaker 36 of FIG. 3 or the sensory stimulusgenerator 16 of FIG. 2. Each time the sleeper draws a breath, the short,quiet hum is produced. The hum is quiet enough to not disturb thesleeper's sleep, and short enough to be distinguishable from subsequenthums and create a subconscious, Pavlovian-like association between thesleeper's breath and the hum. After a time, for example 30–60 breaths,to determine whether the sleeper is pacing (Step 62), a characteristicof the hum, such as the volume, the frequency, the duration, or thetiming, is adjusted slightly. The physiological characteristic ismonitored (Step 60) to determine whether the adjusted hum characteristichad any effect on the sleeper's breathing. If, as anticipated, theadjusted hum characteristic caused a comparable adjustment to thesleeper's physiological characteristic, it may be presumed that thesleeper is pacing with the sleep guidance system. If not, the sleepermay be paced for a longer period of time, using the same, analternative, or an additional physiological characteristic, using analternative sensory stimuli, or with a different adjustment to thecharacteristic of the sensory stimuli.

In one specific example of how the invention may be applied, aparticular sleeper is paced (Step 58) using a soft 60 Hz hum having aduration of 0.5 seconds for 30 breaths. For this sleeper, it waspreviously determined during calibration that this hum had the desiredaffect of pacing the sleeper. To determine whether the sleeper is pacing(Step 62), the hum is adjusted to a soft 50 Hz hum having a duration of0.6 seconds for several additional breaths (e.g. 5–10), and thesleeper's breathing is monitored (Step 60). The necessary adjustments tothe hum may be determined from trial and error, from experience indealing with sleepers, or from the results of calibration tests on thisparticular sleeper. In this example, based upon calibration results, itmay be anticipated that this change would cause the sleeper's breathingrate to slow. Regardless of the change that occurs in the sleeper,however, if the sleeper's breathing rate changes commensurate with thechange in the characteristics of the hum, the sleeper is pacing with thesleep guidance system at some level and is being lead.

Some sleepers may pace easily and require only a few or only lessextreme sensory stimuli being generated to establish a rapport. Othersleepers may require sensory stimuli for a longer time or of greatermagnitude to establish a rapport. A good indication of what sensorystimuli will best pace and lead a sleeper through sleep stages and whatphysiological characteristics indicate that the sleeper's sleep patternsare pacing and leading may be determined through calibrating the systemto the sleeper either before pacing, or by gathering data during one ormore sleep guidance sessions. Because each sleeper is different and mayrespond differently to each sensory stimulus provided or pattern ofsensory stimuli provided, pre-calibrating a system to a particularsleeper may allow a rapport to be more quickly established between asleeper and a sleep guidance system configured according to embodimentsof the present invention. Establishing a personalized sleep profile fora sleeper is included in calibration of the system to the sleeper. Thispersonalized sleep profile may be stored electronically, or otherwise,and transferred from one system to another. As part of calibrating aparticular system to a sleeper (Step 52), the system may receive asleeper's personalized profile from another computer system for use inpacing and leading the sleeper with the present system. By enabling anability to transfer sleep profiles between systems, or for storage orarchiving, a relatively complex system may be used to determine asleeper's personal profile, perhaps in a sleep clinic for example, and arelatively less complex system, such as a remote portable system at thesleeper's home, may be used on a daily basis to help the sleeper sleep.

Once it is determined that a sleeper is pacing, the sleeper is ready tobe lead (Step 64) to a different sleep stage. Leading involves adjustinga characteristic of the sensory stimuli being generated to cause adesirable change in a physiological characteristic of the sleeper. Aswith pacing, the precise sensory stimuli used to initiate a change in aphysiological characteristic of the sleeper or to lead the sleeper to anew sleep stage may be determined through trial and error, throughexperience with other sleepers, or through data obtained duringcalibration. For example, if a sleeper is in Stage 2 sleep,characterized by a slowed heart rate and breathing, a particular sleepermay be lead through Stage 2 sleep to Stage 3 sleep, characterized by yetfurther slowed heart rate, further slowed breathing and relaxed muscles,by producing sensory stimuli having characteristics to initiate slowerbreathing. By specific example, this may involve adjusting the pacingAhum@ described above very slightly over a predetermined time (i.e. 2–15minutes) to gradually slow the breathing and heart rate of the sleeperto a rate characteristic of the sleeper's Stage 3 sleep. To determinewhether the sleeper is following the leading (Step 68), at least onephysiological characteristic is monitored (Step 66) while the sleeper isbeing lead (Step 64).

Once it is determined that the sleeper is following the lead (Step 68),the sleep guidance system, through monitoring the physiologicalcharacteristics of the sleeper, determines whether the sleeper hasreached a new sleep stage (Step 70). This may be done by directmonitoring of the sleeper's brain waves or one or more otherphysiological characteristics of the sleeper indicative of the sleeper'ssleep stage. If calibration was performed previously, the calibrationdata collected may allow the sleep guidance system to monitorphysiological characteristics of the sleeper other than the brain wavesto objectively determine that the sleeper is in a particular sleepstage. However, as will be clear to those of ordinary skill in the art,it is not required by the invention to specifically know which sleepstage the sleeper is in to pace and lead the sleeper. Nevertheless, ifthe sleeper has not reached a new sleep stage (Step 70) or recognizedpattern of one or more physiological characteristics, the systemcontinues to lead the sleeper (Step 64) until the new sleep stage hasbeen reached (Step 70). If the sleeper has reached a new sleep stage(Step 70), the sleep guidance system determines whether it is time towake up from sleep (Step 72). If so, the sleep guidance system may wakethe sleeper (Step 74), or may merely permit the sleeper to wakenaturally from a light sleep. If it is not time for the sleeper to wake(Step 72), the sleep guidance system may continue to either pace and/orlead a sleeper through another sleep stage or cycle. Alternatively, ifthe sleeper is at the final sleep stage (i.e. Stage 1 or 2) and it isonly a short time until the sleeper is to wake, the sleep guidancesystem may pace and/or lead the sleeper through a longer final sleepstage until it is time to wake.

It is anticipated that select embodiments of a sleep guidance system ofthe present invention will be configured to allow a sleeper to select asleep period duration and calculate the optimal time for each sleepstage and the number of sleep cycles to leave the sleeper in a finalsleep stage at the end of the sleep period duration as an optimal sleeppattern for the sleeper. In this way, the sleep guidance system cancustomize the sleep cycle to the sleeper's needs based upon when thesleeper needs to be woken up rather than on the variable time at whichthe sleeper may fall asleep. By example, if a particular sleeperordinarily sleeps for eight (8) hours and needs to wake up, instead, infour (4) hours, the sleeper may select the appropriate wake-up time andthe system will optimize the sleeper's sleep throughout the nightregardless of how long it takes the sleeper to fall asleep. Furthermore,if the sleeper's sleep is disrupted during sleep, the sleep guidancesystem may then recalculate the times for the sleep stages and thenumber of sleep cycles and continue guiding the sleeper through therevised optimal sleep pattern. By receiving feedback from the sleeper inthe form of physiological characteristic responses, the sleep guidancesystem can adapt to a particular sleeper's sleeping habits and to anyenvironment in which the sleeper may choose to sleep, providing thesleeper with optimal sleep for that sleeper in that environment.

It is also anticipated that each time a sleeper is guided by a sleepguidance system of the present invention, the sleeper will more readilypace with the sensory stimuli and follow it. It is contemplated that inembodiments of the invention, rather than pacing and leading using smallphysiological characteristics such as heart rate or breathing, pacingand leading may be performed on a larger scale. For example, it isbelieved that like Pavlov's dogs who were conditioned to salivate whenthey heard a bell, sleepers may be conditioned over time to change sleepstages in response to one or more selected sensory stimuli. In oneparticular embodiment, throughout standard pacing and leading asdiscussed above, or merely while monitoring a sleeper's natural sleeppatterns, sensory stimuli are provided at selected points in a sleeper'ssleep cycle, such as around transitions from one sleep stage to anotheror when a monitored physiological characteristic reaches a significantmilestone or threshold of change for a sleep stage or sleep cycle. Byproducing the sensory stimuli at the same point of the sleep stage everytime the sleeper reaches that point of the sleep stage, a sleeper may beconditioned to move to that point of the sleep stage with physiologicalcharacteristics indicative of that sleep stage in response to thesensory stimuli. In this way, the necessary sensory stimuli for guidinga sleeper through efficient sleep may be reduced over time.

In one particular embodiment of the invention, a sleep guidance systemis calibrated to a particular sleeper in a sleep clinic usingpolysomnography equipment. The sleep guidance system may be calibratedto the sleeper by monitoring the sleeper's sleep patterns, correspondingphysiological characteristics, and changes in the sleeper'sphysiological characteristics in response to selected sensory stimuli asdiscussed previously herein. The sleeper may also be paced and leadduring numerous sleep cycles within the clinic to begin training thesleeper to sleep guidance and to refine calibration of the sleepguidance system data. Subsequently, the sleeper may use a home-versionof the sleep guidance system that includes some polysomnographyequipment for temporary home use to confirm that the sleeper is stilltraining to the sleep guidance and that further calibration is notneeded. The duration of use of the polysomnography equipment dependsupon how readily the subconscious of a sleeper accepts the sleepguidance and how readily a rapport is established. Eventually, only asimple sleep guidance system may be needed which monitors only one ortwo physiological characteristics of the sleeper and paces and leadswith only a single type of sensory stimulus, i.e. sound, light orvibration. As explained previously, the sleeper's personal sleep profilemay be transferred between systems to simplify later calibration byrelatively less complex systems.

As part of conditioning a sleeper to a sleep guidance system, multiplesensory stimuli may be used to cause a desired physiological responseand to tie a sensory trigger to that response. For example, it is knownthat flashing lights into a person's eyes at certain frequencies willcause the person's brain waves to match the frequencies of the flashinglights. To help guide a sleeper through a sleep stage, flashing lightsor other stimulus may initially be used as a primary stimulus to causethe sleeper's brain waves to match a desired frequency of a particularsleep stage at a point in a sleep cycle. The brain waves may bemonitored by appropriate polysomnography equipment to determine whetherthe sleeper is pacing and being lead through sleep stages by the primarysensory stimulus of the lights. A secondary stimulus such as an audibleAhum@ may be used in conjunction with the lights to create anassociation between the Ahum@ and those brain wave patterns evoked bythe lights. Over time, the primary stimulus may be removed and only thesecondary stimulus may be used to evoke the brain wave patterns througheffective conditioning. One advantage of this kind of conditioning isthat less expensive and less complex equipment may be used by a sleeperat home over time to produce the Ahum@ and to monitor other secondaryindicators of the sleeper's sleep stage after the sleeper has beenconditioned for a time using more expensive monitoring and sensorystimulus equipment.

The embodiments and examples set forth herein were presented in order tobest explain the present invention and its practical application and tothereby enable those of ordinary skill in the art to make and use theinvention. However, those of ordinary skill in the art will recognizethat the foregoing description and examples have been presented for thepurposes of illustration and example only. The description as set forthis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the teachings above without departing from the spirit andscope of the forthcoming claims. For example, and without limitation, itis expected that the methods disclosed herein are not limited for usewith human sleepers, but would also work with animals having sleepproblems.

1. A method of guiding a sleep pattern of a sleeper, the methodcomprising: monitoring at least one physiological characteristic of asleeper; generating at least one sensory stimulus to pace the sleeper;and varying the at least one sensory stimulus.
 2. The method of claim 1,further comprising: varying the at least one sensory stimulus; comparingthe variations in the sensory stimulus to the at least one physiologicalcharacteristic of the sleeper; and determining if the sensory stimulusis pacing the sleeper.
 3. The method of claim 2, further comprisingvarying the at least one sensory stimulus to lead the sleeper.
 4. Themethod of claim 2, further comprising: varying the at least one sensorystimulus after it is determined that the sensory stimulus is pacing thesleeper; comparing the variations in the sensory stimulus after thesleeper is being paced to the at least one physiological characteristicof the sleeper; and determining if the sensory stimulus is leading thesleeper.
 5. The method of claim 4, further comprising monitoring the atleast one physiological characteristic of the sleeper until it isdetermined that the sleeper has been successfully led to a destinationsleep stage.
 6. A method of guiding a sleep pattern of a sleeper, themethod comprising: monitoring at least one physiological characteristicof a sleeper indicative of a current sleep stage of the sleeper;determining which sleep stage the sleeper is in prior to generating asensory stimulus; generating at least one sensory stimulus to pace thesleeper; and varying the at least one sensory stimulus to lead thesleeper to a sleep stage different from the current sleep stage.
 7. Themethod of claim 6, wherein monitoring the physiological characteristiccomprises monitoring at least one of heart rate, blood pressure, brainwave pattern, muscle tension, eye movement, respiration, bodytemperature, blood flow, blood oxygen level, blood chemistry, noisiness,moisture, body position and body motion.
 8. The method of claim 6,wherein generating the sensory stimulus comprises generating at leastone of an audible sound, a visible light, a vibration, an electricshock, and an environmental adjustment.
 9. The method of claim 8,wherein the environmental adjustment comprises at least one of atemperature change, a change in air flow, a change in ambient light, anda change in ambient noise.
 10. The method of claim 6, further comprisingdetermining whether the sleeper has moved to the different sleep stagesubsequent to generating the sensory stimulus.
 11. The method of claim6, wherein generating the sensory stimulus to lead the sleeper comprisespacing the sleeper by generating a sensory stimulus in response to eachmeasured change in the physiological characteristic that exceeds apredetermined threshold.
 12. The method of claim 11, wherein generatingthe sensory stimulus to lead the sleeper further comprises adjusting acharacteristic of the sensory stimulus generated.
 13. The method ofclaim 12, wherein adjusting the characteristic of the sensory stimulusgenerated comprises adjusting the sensory stimulus generation to affectat least one physiological characteristic of the sleeper to lead thesleeper to the different sleep stage subsequent to generating thesensory stimulus.
 14. The method of claim 13, further comprisingmonitoring the physiological characteristic to determine whethergenerating the sensory stimulus is encouraging the sleeper to enter thedifferent sleep stage.
 15. The method of claim 6, wherein generating thesensory stimulus to lead the sleeper comprises generating the sensorystimulus to lead the sleeper from a non-rapid eye movement sleep stageto a rapid eye movement sleep stage.
 16. The method of claim 6, furthercomprising indicating a sleep period duration for monitoring thephysiological characteristic and generating sensory stimuli throughoutthe sleep period duration at selected intervals to guide the sleeperthrough sleep stages so that the sleeper is in a sleep stage near anawake stage of sleep around an end of the sleep period duration.
 17. Themethod of claim 16, wherein generating sensory stimuli throughout thesleep period duration at selected intervals comprises generating sensorystimuli continuously throughout the sleep period duration to guide thesleeper through sleep.
 18. The method of claim 6, further comprisinggenerating a sensory stimulus in response to the monitored physiologicalcharacteristic of the sleeper to establish a rapport with the sleeper.19. The method of claim 18, further comprising monitoring the sleeper'sresponse to the sensory stimulus to establish a rapport to determine ifthe sleeper is pacing with the sensory stimulus.
 20. The method of claim6, further comprising generating a sensory stimulus to pace the sleeper.21. The method of claim 20, wherein pacing the sleeper comprises pacingthe physiological characteristic of the sleeper.
 22. The method of claim6, wherein the sensory stimulus stimulates the sleeper's touch sense.23. The method of claim 6, wherein the sensory stimulus stimulates thesleeper's smell sense.
 24. The method of claim 6, wherein the sensorystimulus stimulates the sleeper's sight sense.
 25. The method of claim6, wherein the sensory stimulus stimulates the sleeper's hearing sense.26. The method of claim 6, wherein the sensory stimulus stimulates thesleeper's taste sense.
 27. The method of claim 6, wherein the at leastone physiological characteristic monitored includes at least twophysiological characteristics monitored.
 28. The method of claim 27,wherein the at least two physiological characteristics monitored includea plurality of physiological characteristics monitored.
 29. A method ofguiding a sleep pattern of a sleeper comprising: monitoring at least onephysiological characteristic of the sleeper indicative of NREM sleep;generating a first sensory stimulus having at least one characteristicto pace the sleeper; varying the first sensory stimulus having at leastone characteristic configured to lead the sleeper to enter REM sleep;and monitoring the physiological characteristic to determine whether thefirst sensory stimulus was effective to lead the sleeper to enter REMsleep.
 30. The method of claim 29, further comprising: generating asecond sensory stimulus to pace the sleeper's sleep; leading the sleeperto enter NREM sleep after the sleeper is pacing; and monitoring thephysiological characteristic to determine whether the sleeper enteredNREM sleep.
 31. The method of claim 30, further comprising monitoringthe sleeper's response to determine if the sleeper is pacing with saidsecond sensory stimulus.
 32. The method of claim 30, wherein pacing thesleeper's sleep comprises pacing the physiological characteristic of thesleeper.
 33. The method of claim 29, further comprising: determiningthat a first change in the physiological characteristic of the sleeperis indicative of NREM sleep and that a second change in thephysiological characteristic of the sleeper is indicative of the sleeperentering REM sleep; and guiding the sleeper to enter REM sleep from NREMsleep by leading the sleeper to experience the second change in thephysiological characteristic indicative of the sleeper entering REM. 34.The method of claim 29, further comprising generating a second sensorystimulus in response to the monitored physiological characteristic ofthe sleeper to establish a rapport with the sleeper.
 35. The method ofclaim 29, wherein said first sensory stimulus stimulates the sleeper'stouch sense.
 36. The method of claim 29, wherein said first sensorystimulus stimulates the sleeper's smell sense.
 37. The method of claim29, wherein said first sensory stimulus stimulates the sleeper's sightsense.
 38. The method of claim 29, wherein said first sensory stimulusstimulates the sleeper's hearing sense.
 39. The method of claim 29,wherein said first sensory stimulus stimulates the sleeper's tastesense.
 40. The method of claim 29, wherein the at least onephysiological characteristic monitored includes at least twophysiological characteristics monitored.
 41. The method of claim 40,wherein the at least two physiological characteristics monitored includea plurality of physiological characteristics monitored.
 42. A sleeppattern adjustor comprising: a physiological characteristic monitor; asensory stimulus generator; and a processor operatively associated withthe physiological characteristic monitor and the sensory stimulusgenerator, the processor configured to receive input from thephysiological characteristic monitor indicative of a first sleep stageof a sleeper and provide output to the sensory stimulus generator tocause the sensory stimulus generator to generate at least a firstsensory stimulus in response to the input received from thephysiological characteristic monitor to pace the sleeper, and to varythe first sensory stimulus to lead the sleeper from the first sleepstage to a second sleep stage.
 43. The sleep pattern adjustor of claim42, wherein the physiological characteristic monitor is configured tomonitor at least one physiological characteristic of the sleeper, the atleast one physiological characteristic comprising at least one of heartrate, blood pressure, brain wave patterns, muscle tension, eye movement,respiration, body temperature, blood flow, blood oxygen level, bloodchemistry, noisiness, body position and body motion.
 44. The sleeppattern adjustor of claim 42, wherein the processor is furtherconfigured to pace a sleeper in the one sleep stage by generating atleast a second sensory stimulus in response to a measured change in atleast one physiological characteristic monitored through thephysiological characteristic monitor, and lead the sleeper to the othersleep stage by adjusting a characteristic of the second sensory stimulusgenerated.
 45. The sleep pattern adjustor of claim 44, wherein theprocessor is further configured to receive feedback through thephysiological characteristic monitor indicating whether the sleeper isfollowing the lead to the other sleep stage, and to further adjust thecharacteristic of the sensory stimulus generated to further cause thesleeper to change to the other sleep stage.
 46. The sleep patternadjustor of claim 42, wherein the sensory stimulus generator isconfigured to generate at least one of an audible sound, a visiblelight, a vibration, an electric shock, and an environmental adjustment.47. The sleep pattern adjustor of claim 46, wherein the environmentaladjustment comprises at least one of a temperature change, a change inair flow, a change in ambient light, and a change in ambient noise. 48.The sleep pattern adjustor of claim 42, wherein the processor isconfigured to lead the sleeper from a non-rapid eye movement sleep stageto a rapid eye movement sleep stage.
 49. The sleep pattern adjustor ofclaim 42, wherein the processor is further configured to receive aninput indicating a sleep period duration for monitoring thephysiological characteristic and to generate sensory stimuli throughoutthe sleep period duration at selected intervals to guide the sleeperthrough at least the first and second sleep stages so that the sleeperis in a sleep stage near an awake state around an end of the sleepperiod duration.
 50. The sleep pattern adjustor of claim 49, wherein theprocessor is further configured to generate sensory stimuli continuouslythroughout the sleep period duration to guide the sleeper through sleep.51. The sleep pattern adjustor of claim 42, wherein at least one of thephysiological characteristic monitor and the sensory stimulus generatorcommunicates with the processor using wireless technology.
 52. The sleeppattern adjustor of claim 42, wherein the processor is furtherconfigured to generate a sensory stimulus in response to the monitoredphysiological characteristic of the sleeper to establish a rapport withthe sleeper.
 53. The sleep pattern adjustor of claim 52, wherein theprocessor is further configured to monitor the sleeper's response to thesensory stimulus and generate a responsive sensory stimulus to establisha rapport and pace the sleeper with the sensory stimulus.
 54. The sleeppattern adjustor of claim 42, wherein the processor is furtherconfigured to generate a sensory stimulus to pace at least onephysiological characteristic of the sleeper.
 55. The sleep patternadjustor of claim 42, wherein the processor is further configured togenerate a sensory stimulus to lead the sleeper to another sleep stage.56. The sleep pattern adjustor of claim 42, wherein the sensory stimulusgenerator is configured to stimulate the sleeper's touch sense.
 57. Thesleep pattern adjustor of claim 42, wherein the sensory stimulusgenerator is configured to stimulate the sleeper's smell sense.
 58. Thesleep pattern adjustor of claim 42, wherein the sensory stimulusgenerator is configured to stimulate the sleeper's sight sense.
 59. Thesleep pattern adjustor of claim 42, wherein the sensory stimulusgenerator is configured to stimulate the sleeper's hearing sense. 60.The sleep pattern adjustor of claim 42, wherein the sensory stimulusgenerator is configured to stimulate the sleeper's taste sense.
 61. Thesleep pattern adjustor of claim 42, wherein the physiologicalcharacteristic monitor monitors at least two physiologicalcharacteristics.
 62. The sleep pattern adjustor of claim 61, wherein thephysiological characteristic monitor monitors a plurality ofphysiological characteristics.
 63. An apparatus for guiding a sleeppattern of a sleeper to change between NREM and REM sleep, the apparatuscomprising: a physiological characteristic monitor configured to monitorat least one physiological characteristic of a sleeper; a sensorystimulus generator configured to generate at least one sensory stimulusin response to the physiological characteristic of the sleeper to pacethe sleeper; and a processor operatively associated with thephysiological characteristic monitor and the sensory stimulus generator,the processor configured to receive input from the physiologicalcharacteristic monitor indicative of a NREM sleep stage, and provideoutput to the sensory stimulus generator to vary the at least onesensory stimulus to lead the sleeper to a REM sleep stage.
 64. Theapparatus of claim 63, wherein the processor is further configured toreceive input from the physiological characteristic monitor indicativeof the REM sleep stage, and provide output to the sensory stimulusgenerator to lead the sleeper to change to the NREM sleep stage.
 65. Theapparatus of claim 63, wherein the processor is further configured todetermine which physiological characteristic of the sleeper isindicative of the NREM sleep stage and which physiologicalcharacteristic of the sleeper is indicative of the sleeper entering theREM sleep stage, and to guide the sleeper to enter the REM sleep stageby causing the sensory stimulus generator to generate the at least onesensory stimulus to lead the sleeper to experience the physiologicalcharacteristic indicative of the sleeper entering the REM sleep stage.66. The apparatus of claim 63, wherein the at least one physiologicalcharacteristic monitored includes at least two physiologicalcharacteristics monitored.
 67. The apparatus of claim 66, wherein the atleast two physiological characteristics monitored include a plurality ofphysiological characteristics monitored.